Non-marring horizontal clamp

ABSTRACT

A strong, compact clamp of simple construction is presented for lifting flat workpieces such as steel plates in a horizontal position without marring the surface of the plate being handled. The main body of the clamp comprises two identical parallel generally C-shaped planar body portions which are inserted into slots in a flat clamping surface body portion and welded there. Between the front portions of the upper arms of the C-clamp members is pivotally mounted a clamping lever having an eccentric clamping surface which presses against a separate flat clamping plate which has a pin and slot connection with the lower end of the clamping lever. The upper end of the clamping lever is provided with means for attaching a lifting device there. A modification shows a fixed column rising above the clamping surface body portion, a clamping bracket pivotally supporting the clamping lever and movable vertically on the column with a height-adjustable connection between the bracket and column.

States Patent [1 1 .lanoslto 1 NON-MARRING HORIZONTAL CLAMP [76] Inventor: Michael J. Janosko, 2421 Bridge Ave., Cleveland, Ohio 44113 22 Filed: Oct. 1, 1973 21 App]. No.: 402,406

[52] U.S. Cl. 24/248 C, 294/104 [51] lint. Cl B66c 1/48, A44b 21/00 [58] Field of Search 294/D1G. 1, DIG. 2, 101, 294/104; 24/248 PC, 249 PP, 249 WL, 248 I R, 263 R1, 248 C, 243 CC, 263 PC [56] References Cited UNITED STATES PATENTS 256,626 4/1882 Berstler 24/248 C UX 627,401 6/1899 Edwards 294/104 X 713,485 11/1902 Neumeier 294/104 1,311,089 7/1919 Parker 24/248 PC 2,370,528 2/1945 Fontaine.... 294/104 2,412,555 12/1946 Baker 294/104 2,654,629 10/1953 Renfroe 294/101 3,427,016 2/1969 Harris 24/263 PJ X 3,659,890 5/1972 Renfroe 294/104 Primary ExaminerDonald A. Griffin Attorney, Agent, or FirmBaldwin, Egan, Walling & Fetzer 5 7] ABSTRACT A strong, compact clamp of simple construction is presented for lifting flat workpieces such as steel plates in a horizontal position without marring the surface of the plate being handled.- The main body of the clamp comprises two identical parallel generally C- shaped planar body portions which are inserted into slots in a flat clamping surface body portion and welded there. Between the front portions of the upper arms of the C-clamp members is pivotally mounted a clamping lever having an eccentric clamping surface which presses against a separate flat clamping plate which has a pin and slot connection with the lower end of the clamping lever. The-upper end of the clamping lever is provided with means for attaching a lifting device there. A modification shows a fixed column rising above the clamping surface body portion, a clamping bracket pivotally supporting the clamping lever and movable vertically on the column with a height-adjustable connection between the bracket and column.

12 Claims, 11 Drawing Figures Dec. 3, 1974 PATENTEE, DEC 3 I974 SHEET 2 [IF 2 FIGJO 1 NON-MARRING HORIZONTAL CLAMP BACKGROUND OF THE INVENTION Many clamps are known for the handling of steel plates and the like in a horizontal position when moving the same from one place to another. Many of these clamps have the disadvantage that they tend to mar the surfaces of the steel plates as the clamp is moved into a clamping position. The object of the present invention is to provide a separate clamping plate which is always in the proper position on the clamp and which takes the relative movement between the clamping member and the clamping plate, thus protecting the surface of the steel being handled from any marring defects.

The construction and operation of the clamp of this invention is shown in the accompanying drawings and the essential features thereof will be set forth in the appended claims.

In the drawings,

FIG. 1 is a side elevation of the clamp of this invention;

FIG. 2 is a top plan view of the same taken along the line 2-2 of FIG. 1;

FIG. 2A is a plan view greatly reduced of a flat clamping surface body portion which appears in FIGS. 1 and 2;

- FIGS. 3 and 4 arefront and rear elevations, respectively, of the clamp shown in FIG. 1;

FIG. 5 is anelevational view taken from the same position as FIG. 1 but showing the parts of the clamp in clamping position for lifting a steel plate;

FIG. 6 is an elevational view of a modification wherein the support for the clamping lever is vertically adjustable;

FIG. 7 is a top plan view of FIG. 6;

FIG. 8 is a view similar to FIG. 6 but showing another position of the parts; while FIGS. 9 and 10 are top plan and elevational views of a modification of "the structure shown in FIGS. 6 through 8, which provides a different arrangement of the adjustable dog which engages the vertical column.

The main body portion of the clamp consists of two generally -C-shape body portions and a flat clamping surface body portion. Two identical parallel generally C-shape planar body portions 10 have intermediate portions 10a with upper arm portions 10b and lower arm'portions 10c extending substantially at right angles to the intermediate portion. The flat clamping surface bodyportion 11 is shown in blank form in FIG. 2A as having two parallel slots 11a opening toward one end of the clamping surface body portion and of a width and length to snugly engage the intermediate portions 10a of the two C-shape body portions. When'these three parts are assembled, they are rigidly welded together as indicated at 12. v

A clamping lever 13 is provided having a through opening at 1311 by which it is connected by means of pivot pin to the forward ends of the upper arms 10b of the C-shape clamp portions. To this end, the pin 14 is passed through suitable registering openings 15 in the arm portions 10b. The pin 14 has a head at one end and the other end is embraced by a washer 16 held in place by a cotter pin 17. At its upper end, the clamping lever is provided with means for attaching a lifting device which in this case is shown as an opening 18 suitable to receive a cable or chain normally suspended from a lifting crane hook.

The clamping lever has a clamping cam 13b below the level of the pivot pin 14' and eccentric relative to the pivot pin. Note that the eccentricity of this clamping cam increases smoothly in a forward direction.

A clamping plate 19 has a pin and slot suspension beneath the clamping lever 13. The form shown in the drawings includes two inverted U-shape members 20 rigidly secured as by welding their free ends to the upper face of the clamping plate 19. Preferably, these U-shape members are substantially evenly spaced between the front and the rear edges of the clamping plate 19. A pin 21 extends at right angles to the clamping lever 13 and is rigidly secured thereto, as by welding, near the cam 13b leaving the same projecting on opposite sides of the camming lever so that the opposite ends of this pin extend into the openings of the U- shape members 20. r

Means is provided for guiding the clamping plate 19 laterally relative to the C-shape body portions 10. As seen in FIGS. 1 and 2, this comprises a tail 19a rigid with the clamping plate 19, and preferably integral therewith, and extending rearwardly centrally from the rear edge of the clamping plate 19. This tail extends between the parallel vertical C-shape body portions 10 as clearly viewed in FIG. 2. This assures that the clamping plate 19 will not swing out of the proper position as it moves up and down on the pin and slot connection 20, 21.

The upper flat clamping surface of the body member 11 and the lower flat clamping surface of the clamping plate 19 have smooth flat faces which are presented toward the steel plate to be lifted.

The operation of the invention will clearly be understood from a discussion of FIG. 5. Shown in dot-dotdash lines is a piece of steel plate 22 which normally would be lifted by pairs of clamps according to this invention engaging on opposite edges of the plate to be -lifted. One pair might be used on opposite sides of the plate or a plurality of pairs. The clamping lever 13 is moved in a clockwise direction about the pin 14 until the cam 13b is sufficiently lifted to enter the plate 22 into the clamp as shown in FIG. 5. Because of the construction described, the tail 19a will tilt the forward end of the clamping plate 19 upwardly so that the steel plate more readily enters the clamps. Upon applying a lifting force at 23' to a cable or the like attached through the opening 18 of the clamping lever, the load is lifted and at the same time the clamping lever 13 is urged in a counterclockwise direction causing the cam 13b to press tightly against the upper surface of the clamping plate 19, the pin and slot connection 20, 21 permitting this action.

The clamp of this invention is very strong and efficient. A clamp constructed using l/2 inch steel plate for the C-shape body portions 10, and using a pair of such clamps, withstood a pull of 30 tons or 15 tons per idly connected between them. This bracket embraces the column 23.

The bracket side walls have forwardly extending portions having registering openings in which to receive the pin 14 which provides the pivot connection between the clamping lever 13 as in the previously described embodiment. The cam surface 13b and the pin and slot connection 20, 21 and the clamping plate 19 are like those previously described and are given similar reference characters. The opening 18 through the clamping lever at the top is for the attachment of a wire rope or chain during the lifting operation as previously described.

Dog means is provided for supporting the bracket 24 in various positions vertically along the column 23. In FIGS. 6, 7 and 8, this comprises two dogs 25, each of which is an integral portion of one of the forwardly extending portions 24a. As shown in the drawings, each dog has a notch-engaging nose which is complementary to the notches 23a. In a preferred form of the invention, the notches have the shape of the major portion of a semicircle and the nose of each dog 25 is complementary and adapted to fit snugly into almost the entire surface of each notch which it engages.

Spring means is provided normally urging the dogs 25 into the notches 230. As clearly seen in the drawings, a preferred form is a leaf spring 26 which has its lower end 26a firmly secured by screws 26b to an outwardly projecting flange 27 on the back wall 24b of the bracket. The upper end of the spring is bent outwardly at 260 so as to guide the upper end of the spring as it is manipulated. Preferably a handle 28 is provided extending at right angles to the rear wall 24b of the bracket 24 which may be grasped by an operator so as to compress spring 26 between the bracket wall 24b and the rear wall of the C-shape column 23 so as to move the dogs 25 out of a given set of notches 23a after which the bracket may be moved up or down as required and the dogs then allowed to engage in another set of notches 23a. Because of the complementary engagement between the dogs and the receiving notches 23a, this clamp can withstand very heavy loads without any failure.

Preferably a pin 29 is provided across the two parallel forwardly extending arms ofthe column 23 so as to prevent lifting the bracket out of engagement with the column 23.

Preferably, but not necessarily, the two side walls 23b of the column 23 extend downwardly below the base 22 and have integral portions 23c extending below the base 22 and rigidly welded thereto at 30. The rear wall 23d of the vertical column also extends in an integral manner into the portion 230 below the base 22.

In the modification of FIGS. 9 and 10, all of the parts are exactly like those described in connection with FIGS. 6, 7 and 8 except with regard to the dog which provides the adjustable height of the bracket relative to the column. Here the forwardly extending arms 24a of the bracket 24' are bent inwardly at their outer ends to snugly engage the cam lever 13 and to receive the pivot pin 14' which pivotally connects the lever 13 and the bracket 24. The dog means 25' consists of a pin which passes through suitable openings in the side walls of bracket 24' and is held in place by a head 25a and -a cotter pin 25b. It will be noted in FIG. that the diameter of the pin is complementary to the notches 23a so as to firmly hold the bracket 24a in any adjusted position while it is handling a load.

The operation of the invention as modified in FIGS. 6 through 10 is like that of the first embodiment except for the height adjustability. To accommodate a steel plate of any given thickness such as shown at 31 in dotdash lines of FIG. 8, the operator grasps the handle 28 and pushes the bracket 24 or 24' forwardly while causing the back wall 24b of the bracket to compress the leaf spring 26 so as to release the dogs 25 or 25' from the notches 23a in which they were previously engaged. The bracket may then be moved to an adjusted position capable of receiving and clamping upon the plate 31 to be handled. The operator then releases the handle 28 so as to re-engage the dogs 25 in the selected notches 23a. Then upon applying a lifting force at the connection 18 of the clamping lever, the load is lifted and at the same time the clamping lever 13 is urged in a counterclockwise direction causing the cam surface 13b to press tightly against the upper surface of the clamping plate 19, the pin and slot connection 20, 21 permitting this action. Here again, the lower surface of the clamping plate 19 and the upper surface 22a of the clamping surface portion of the base 22 are smooth and thus do not mar the plate being handled.

What is claimed is:

l. A non-marring clamp for lifting flat workpieces such as steel plates in a horizontal position, comprising abase including an upwardly facing flat clamping surface, means fixed to one side of said surface and extending upwardly and there providing an inwardly extending projection over said surface for supporting an oscillatatable clamping lever, a clamping lever having a pivot connection intermediate its ends to the forward end of said projection, said clamping lever having a clamping cam below the level of said pivot connection eccentric relative to said pivot connection and of which the eccentricity increases in a forward direction, a clamping plate having a pin and slot connection with the lower portion of said clamping lever near said eccentric clamping cam holding said clamping plate loosely and generally parallel to said flat clamping surface, said clamping plate and said clamping surface having smooth flat faces presented toward a workpiece to be lifted, and means for'attaching a lifting device to the upper portion of said clamping lever.

2. A non-marring clamp as defined in claim 1, wherein said means fixed to one side of said clamping surface comprises at least one C-shape member having a lever arm fixed to the under side of said clamping surface, and having an upper arm providing said inwardly extending projection.

3. A non-marring clamp as defined in claim 1, wherein said means fixed to one side of said clamping surface comprises a vertical column rigid with said base 1 and having a series of dog-receiving notches opening toward said lever, a clamping bracket embracing said column and having parallel vertically extending side walls and a rear wall rigidly connected between them, said side walls having forwardly extending portions providing said inwardly extending projection, said pivot connection passing through said forwardly extending portions, dog means rigidly carried by said forwardly extending portions in position to enter a selected one of said series of notches, and spring means normally engaging said dog means into said notches.

'4. A non-marring clamp as defined in claim 3, wherein said column is U-shape in horizontal section opening inwardly and having two parallel arms in which said notches are formed.

5. A non-marring clamp as defined in claim 4, wherein said dog means comprises two dogs having notch-engaging portions complementary to said notches, each an integral part of one of said forwardly extending portions.

6. A non-marring clamp as defined in claim 4, wherein said dog means comprises a pin fitting snugly into said notches.

7. A non-marring clamp as defined in claim 3, wherein said spring means comprises a leaf spring exerting tension between said bracket end wall and said column.

8. A non-marring clamp for lifting flat workpieces such as steel plates in horizontal position, comprising an integral generally C-shape main body portion having at least one lower arm means carrying an upwardly facing flat clamping surface and having at least one upper arm means above and generally parallel to said flat clamping surface, a clamping lever having a pivot connection intermediate its ends to the forward end of said upper arm means, said clamping lever having a clamping cam below the level of said pivot connection eccentric relative to said pivot connection and of which the eccentricity increases in a forward direction, a clamping plate having a pin and slot connection with the lower portion of said clamping lever near said eccentric clamping cam holding said clamping plate loosely and generally parallel to said flat clamping surface, said clamping plate and said clamping surface having smooth flat faces presented toward a workpiece to be lifted, and means for attaching a lifting device to the upper portion of said clamping lever.

9. A non-marring clamping as defined in claim 8, wherein said clamping plate has substantially the area of said flat clamping surface forward of said intermediate portions of said C-shape body portions.

10. A non-marring clamp as defined in claim 9, wherein said means guiding said clamping plate laterally relative to said C-shape body portions comprises a tail rigid with said clamping plate and extending rearwardly centrally from the rear edge thereof and extending loosely between the intermediate portions of said C-shape body portions.

11.A non-marring clamp as defined in claim 10, wherein said U-shape members are substantially evenly spaced between the front and rear edges of said'clamping plate, whereby the weight of said tail biases the front edge of said plate upwardly in position to grip a flat workpiece.

12. A non-marring clamp for lifting flat workpieces such as steel plates in horizontal position, comprising two identical parallel generally C-shaped planar body portions spaced at a predetermined distance and vertical when in use, each said body portion being an integral member, each said C-shape body portion having an intermediate portion and upper and lower arm portions extending at substantially right angles thereto, a flat clamping surface body portion wider than said predetermined distance, there being two parallel slots opening at one end of said clamping surface body portionand of a width to snugly engage said two parallel C- shape body intermediate portions respectively and said body portions welded to each other there with said clamping surface body portion resting on said lower arm portions, a clamping lever having a through opening intermediate its ends, a pivot pin through said opening and through the forward ends of said upper arm portions, said clamping lever having a clamping cam below the level of said pivot pin and eccentric relative to said pivot pin, said eccentricity of said cam increasing smoothly in a forward direction, a clamping plate, two inverted U-shape members rigidly secured at their free. ends to the upper face of said clamping plate in mutual registration and spaced slightly farther than the thickness of said clamping lever, a pin extending at right angles to said clamping lever and rigidly secured thereto near said cam and projecting on opposite sides of said lever with its opposite ends extending into the openings of said U-shape members, said clamping plate and flat clamping surface having smooth flat faces presented toward a workpiece to be lifted, means guiding said clamping plate laterally relative to said C-shape body portions, and means for attaching a lifting device to the upper portion of said clamping lever. 

1. A non-marring clamp for lifting flat workpieces such as steel plates in a horizontal position, comprising a base including an upwardly facing flat clamping surface, means fixed to one side of said surface and extending upwardly and there providing an inwardly extending projection over said surface for supporting an oscillatatable clamping lever, a clamping lever having a pivot connection intermediate its ends to the forward end of said projection, said clamping lever having a clamping cam below the level of said pivot connection eccentric relative to said pivot connection and of which the eccentricity increases in a forward direction, a clamping plate having a pin and slot connection with the lower portion of said clamping lever near said eccentric clamping cam holding said clamping plate loosely and generally parallel to said flat clamping surface, said clamping plate and said clamping surface having smooth flat faces presented toward a workpiece to be lifted, and means for attaching a lifting device to the upper portion of said clamping lever.
 2. A non-marring clamp as defined in claim 1, wherein said means fixed to one side of said clamping surface comprises at least one C-shape member having a lever arm fixed to the under side of said clamping surface, and having an upper arm providing said inwardly extending projection.
 3. A non-marring clamp as defined in claim 1, wherein said means fixed to one side of said clamping surface comprises a vertical column rigid with said base and having a series of dog-receiving notches opening toward said lever, a clamping bracket embracing said column and having parallel vertically extending side walls and a rear wall rigidly connected between them, said side walls having forwardly extending portions providing said inwardly extending projection, said pivot connection passing through said forwardly extending portions, dog means rigidly carried by said forwardly extending portions in position to enter a selected one of said series of notches, and spring means normally engaging said dog means into said notches.
 4. A non-marring clamp as defined in claim 3, wherein said column is U-shape in horizontal section opening inwardly and having two parallel arms in which said notches are formed.
 5. A non-marring clamp as defined in claim 4, wherein said dog means comprises two dogs having notch-engaging portions complementary to said notches, each an integral part of one of said forwardly extending portions.
 6. A non-marring clamp as defined in claim 4, wherein said dog means comprises a pin fitting snugly into said notches.
 7. A non-marring clamp as defined in claim 3, wherein said spring means comprises a leaf spring exerting tension between said bracket end wall and said column.
 8. A non-marring clamp for lifting flat workpieces such as steel plates in horizontal position, comprising an integral generally C-shape main body portion having at least one lower arm means carrying an upwardly facing flat clamping surface and having at least one upper arm means above and generally parallel to said flat clamping surface, a clamping lever having a pivot connection intermediate its ends to the forward end of said upper arm means, said clamping lever having a clamping cam below the level of said pivot connection eccentric relative to said pivot connection and of which the eccentricity increases in a forward direction, a clamping plate having a pin and slot connection with the lower portion of said clamping lever near said eccentric clamping cam holding said clamping plate loosely and generally parallel to said flat clamping surface, said clamping plate and said clamping surface having smooth flat faces presented toward a workpiece to be lifted, and means for attaching a lifting device to the upper portion of said clamping lever.
 9. A non-marring clamping as defined in claim 8, wherein said clamping plate has substantially the area of said flat clamping surface forward of said intermediate portions of said C-shape body portions.
 10. A non-marring clamp as defined in claim 9, wherein said means guiding said clamping plate laterally relative to said C-shape body portions comprises a tail rigid with said clamping plate and extending rearwardly centrally from the rear edge thereof and extending loosely between the intermediate portions of said C-shape body portions.
 11. A non-marring clamp as defined in claim 10, wherein said U-shape members are substantially evenly spaced between the front and rear edges of said clamping plate, whereby the weight of said tail biases the front edge of said plate upwardly in position to grip a flat workpiece.
 12. A non-marring clamp for lifting flat workpieces such as steel plates in horizontal position, comprising two identical parallel generally C-shaped planar body portions spaced at a predetermined distance and vertical when in use, each said body portion being an integral member, each said C-shape body portion having an intermediate portion and upper and lower arm portions extending at substantially right angles thereto, a flat clamping surface body portion wider than said predetermined distance, there being two parallel slots opening at one end of said clamping surface body portion and of a width to snugly engage said two parallel C-shape body intermediate portions respectively and said body portions welded to each other there with said clamping surface body portion resting on said lower arm portions, a clamping lever having a through opening intermediate its ends, a pivot pin through said opening and through the forward ends of said upper arm portions, said clamping lever having a clamping cam below the level of said pivot pin and eccentric relative to said pivot pin, said eccentricity of said cam increasing smoothly in a forward direction, a clamping plate, two inverted U-shape members rigidly secured at their free ends to the upper face of said clamping plate in mutual registration and spaced slightly farther than the thickness of said clamping lever, a pin extending at right angles to said clamping lever and rigidly secured thereto near said cam and projecting on opposite sides of said lever with its opposite ends extending into the openings of said U-shape members, said clamping plate and flat clamping surface having smooth flat faces presented toward a workpiece to be lifted, means guiding said clamping plate laterally relative to said C-shape body portions, and means for attaching a lifting device to the upper portion of said clamping lever. 